According to the applicable U.S. patent Classification Definitions, this invention is classified as "CLASS 343, COMMUNICATIONS: RADIO WAVE ANTENNAS".
The Folded Unipole Antenna (also known as Folded Monopole Antenna) is a well known vertical type of antenna , formed by a vertical tower of constant cross section dressed with a set of so called fold-wires. The descend vertical fold-wires are all parallel to the tower, externally located and equidistant from the tower geometric center, from its top till the bottom of the tower, without making any electrical contact with the tower (except at the top of the tower, where the fold-wires are electrically connected to the tower structure). Near the ground area, the fold-wires are electrically connected together through an horizontal positioned "O" ring, made of conductive metal (generally copper tubing). The "O" ring is centered in relation to the center of the tower cross section polygon. The "O" ring is the feed point of the antenna. The base of the tower structure is electrically connected to ground.
It has been, along all these years to the designer, a serious difficulty pertaining to all types of antennas the reactance component of the antenna input impedance. The reactance certainly limits the antenna bandwidth (its inherent Q factor is high), it turns more difficult the design of the associated tuning unit, etc. The present invention, which applies to the folded unipole type of antenna, simply overcomes this mentioned difficulty by making the reactive component of the input impedance of the folded unipole antenna equals to zero, so turning the antenna self-resonant at the operating frequency, i.e., its input impedance is purely resistive.
The folded unipole antenna has application in Long Wave Broadcasting (commonly used in Europe), in MW Broadcasting, and in the Amateur Radio 160 meters band; the self-resonant type, object of this invention, will certainly improve the quality transmission on these services just mentioned, as well as other services that might adopt it.